A database of wavefront measurements for laser system modeling, optical component development and fabrication process qualification (open access)

A database of wavefront measurements for laser system modeling, optical component development and fabrication process qualification

In the second half of the 1990`s, LLNL and others anticipate designing and beginning construction of the National Ignition Facility (NIF). The NIF will be capable of producing the worlds first laboratory scale fusion ignition and bum reaction by imploding a small target. The NIF will utilize approximately 192 simultaneous laser beams for this purpose. The laser will be capable of producing a shaped energy pulse of at least 1.8 million joules (MJ) with peak power of at least 500 trillion watts (TV). In total, the facility will require more than 7,000 large optical components. The performance of a high power laser of this kind can be seriously degraded by the presence of low amplitude, periodic modulations in the surface and transmitted wavefronts of the optics used. At high peak power, these phase modulations can convert into large intensity modulations by non-linear optical processes. This in turn can lead to loss in energy on target via many well known mechanisms. In some cases laser damage to the optics downstream of the source of the phase modulation can occur. The database described here contains wavefront phase maps of early prototype optical components for the NIF. It has only recently become possible …
Date: April 12, 1995
Creator: Wolfe, C. R.; Lawson, J. K.; Aikens, D. M. & English, R. E.
Object Type: Article
System: The UNT Digital Library
A direct steam heat option for hydrothermal treatment of municipal solid waste (open access)

A direct steam heat option for hydrothermal treatment of municipal solid waste

A conceptual process for producing a gasifiable slurry from raw municipal solid waste (MSW) using direct steam heating is outlined. The process is based on the hydrothermal decomposition of the organic matter in the MSW, which requires the MSW to be heated to 300-350{degrees}C in the presence of water. A process model is developed and it is shown, based on preliminary estimates of the hydrothermal reaction stoichiometry, that a process using multiple pressure vessels, which allows recovery of waste heat, results in a process capable of producing a product slurry having a 40 wt % solids content with no waste water emissions. Results for a variety of process options and process parameters are presented. It is shown that the addition of auxiliary feedstock to the gasifier, along with the MSW derived slurry, results in more efficient gasification. It is estimated that 2.6 kmol/s of hydrogen can be produced from 30 kg/s (2600 tonne/day) of MSW and 16 kg/s of heavy oil. Without the additional feedstock, heavy oil in this case, only 0.49 kmol/s of hydrogen would be produced.
Date: April 12, 1995
Creator: Thorsness, C.B.
Object Type: Report
System: The UNT Digital Library
2D and 3D ablation front hydrodynamic instability experiments on Nova (open access)

2D and 3D ablation front hydrodynamic instability experiments on Nova

Single-mode experiments have been conducted on the Nova laser to examine the effect of perturbation shape on ablation front Rayleigh-Taylor growth. The perturbations investigated had the same magnitude wave vector k=(k{sub x}{sup 2}+k{sub y}{sup 2}){sup 1/2} and the same initial amplitude. The shapes corresponded to 2D {lambda}=50 {mu}m, 3D square k{sub x}=k{sub y}, and stretched k{sub x}=3k{sub y} perturbations. We observed that the 3D perturbations grew more than the 2D perturbation. Numerical simulations in 2D and 3D arc in agreement, showing the most symmetric modes growing the largest.
Date: April 12, 1995
Creator: Remington, B. A.; Marinak, M. M. & Weber, S. V.
Object Type: Article
System: The UNT Digital Library
ICF burn-history measurments using 17-MeV fusion gamma rays (open access)

ICF burn-history measurments using 17-MeV fusion gamma rays

Fusion reaction rate for inertial-confinement fusion (ICF) experiments at the Nova Laser Facility is measured with 30-ps resolution using a high-speed neutron detector. We are investigating a measurement technique based on the 16.7-MeV gamma rays that are released in deuterium-tritium fusion. Our concept is to convert gamma-ray energy into a fast burst of Cerenkov light that can be recorded with a high-speed optical detector. We have detected fusion gamma rays in preliminary experiments conducted at Nova where we used a tungsten/aerogel converter to generate Cerenkov light and an optical streak camera to record the signal.
Date: April 12, 1995
Creator: Lerche, R. A.; Cable, M. D. & Dendooven, P. G.
Object Type: Article
System: The UNT Digital Library
Development and demonstration of a teleoperated modular {open_quotes}snake{close_quotes} robot system. Final report, September 30, 1986--December 31, 1993 (open access)

Development and demonstration of a teleoperated modular {open_quotes}snake{close_quotes} robot system. Final report, September 30, 1986--December 31, 1993

The U.S. Department of Energy has provided support to four universities and the Oak Ridge National Laboratory in order to pursue research leading to the development and deployment of advanced robotic systems capable of performing tasks that generate significant occupational radiation exposure and/or whose execution times can be reduced if performed by an automated system. The goal was to develop advanced robotic systems capable of performing surveillance, maintenance, and repair tasks in nuclear facilities and other hazardous environments. The approach to achieving the program objective was a transition from teleoperation to the capability of autonomous operation within three successive generations of robotic systems. The robotic system will always have the capability to request human assistance. The development of general purpose robots to perform skilled labor tasks in restricted environments was shown to have extensive payback in areas of energy systems (nuclear and fossil units), chemical plants, fire fighting, space operations, underwater activities, defense, and other hazardous activities. The strategy that was used to achieve the program goals in an efficient and timely manner consisted in utilizing, and advancing where required, state-of-the-art robotics technology through close interaction between the universities and the manufacturers and operators of nuclear power plants. The research …
Date: April 12, 1995
Creator: Tesar, D. & Hooper, R.
Object Type: Report
System: The UNT Digital Library
Limits on Annulus Air Outages in Types 1, 2, and 3 Waste Tanks (open access)

Limits on Annulus Air Outages in Types 1, 2, and 3 Waste Tanks

An evaluation was performed on the impact of abnormal air flow conditions on the structural integrity of Types 1, 2, and 3 waste tanks. Warm, dry air in the annular space is necessary to preclude low temperature embrittlement and corrosive conditions for the carbon steel materials. For Type 1 and 2 tanks the annulus air system should be repaired within a month to minimize the potential for low temperature embrittlement and corrosive conditions, for Tanks 29-34, which are Type 3 tanks, it is recommended that the system be repaired within two months to minimize the potential for low temperature embrittlement. For all other Type 3 tanks repair of the system within six months is adequate to minimize general corrosion.
Date: April 12, 1995
Creator: Wiersma, B.J. & Sindelar, R. L.
Object Type: Report
System: The UNT Digital Library
Functional design criteria for the retained gas sampler system (open access)

Functional design criteria for the retained gas sampler system

A Retained Gas Sampler System (RGSS) is being developed to capture and analyze waste samples from Hanford Flammable Gas Watch List Tanks to determine both the quantity and composition of gases retained in the waste. The RGSS consists of three main components: the Sampler, Extractor, and Extruder. This report describes the functional criteria for the design of the RGSS components. The RGSS Sampler is based on the WHC Universal Sampler design with modifications to eliminate gas leakage. The primary function of the Sampler is to capture a representative waste sample from a tank and transport the sample with minimal loss of gas content from the tank to the laboratory. The function of the Extruder is to transfer the waste sample from the Sampler to the Extractor. The function of the Extractor is to separate the gases from the liquids and solids, measure the relative volume of gas to determine the void fraction, and remove and analyze the gas constituents.
Date: April 12, 1995
Creator: Wootan, D. W.
Object Type: Report
System: The UNT Digital Library
Workshop in computational molecular biology, April 15, 1991--April 14, 1994 (open access)

Workshop in computational molecular biology, April 15, 1991--April 14, 1994

Funds from this award were used to the Workshop in Computational Molecular Biology, `91 Symposium entitled Interface: Computing Science and Statistics, Seattle, Washington, April 21, 1991; the Workshop in Statistical Issues in Molecular Biology held at Stanford, California, August 8, 1993; and the Session on Population Genetics a part of the 56th Annual Meeting, Institute of Mathematical Statistics, San Francisco, California, August 9, 1993.
Date: April 12, 1995
Creator: Tavare, S.
Object Type: Article
System: The UNT Digital Library
FIRE HAZARDS ANALYSIS FOR THE FUEL SUPPLY SYSTEM - ESF PACKAGE 1E (open access)

FIRE HAZARDS ANALYSIS FOR THE FUEL SUPPLY SYSTEM - ESF PACKAGE 1E

The purpose of the fire hazards analysis is to comprehensively assess the risk from fire within individual fire areas in accordance with US. Department of Energy (DOE) Order 5480.7h (Reference 4.4.7.4). This document will assess the fire hazard risk within the Exploratory Studies Facility (ESF) fuel supply system, Package 1E, and evaluate whether the following objectives are met: (1) Ensure that property damage from fire and related perils do not exceed an acceptable level. (2) Provide input to the facility Safety Analysis Report (SAR).
Date: April 12, 1995
Creator: Ruonavaara, N.M.
Object Type: Report
System: The UNT Digital Library